Basement cracks in new construction

[Tater Salad]

Looked at a spec home today that had a fairly good sized crack in the foundation floor (took lots of pretty pics). There was also an area of the floor that looked like a speed bump, like an attempt was made to patch another crack. No moisture, and both sides of the crack looked level.

This house is less than a year old. I called for an inspection by someone who knows a crack from a crack, but I know I will get the calls tomorrow.

I'm characteristically very conservative with things like this, and want some feedback as to what others think. Is this common? The soil in this area is clay, and I have seen some older homes with cracks but not usually in one so new.

Hoping someone out there will tell me that it is a problem so that I will feel justified when I stand my ground about the inspection (which I always do, can't hurt, right?). Anybody know about cracks on the floor, and not the walls?

 

[Mountain Man]

Call for an engineering inspection.
Some years ago, I had to deal with a house that formed a major crack in the basement, is was only a few months old. It turned out to be a nightmare as the house was built on fill dirt, contaminated with sand-silt, and even had logs buried under a loosely compacted clay level. It appears that the previous land owner used that site to dump brush, trees and other "natural" land fill things.

 

[Tater Salad]

Mel

Thanks for the quick response. I thought those builders got engineers reports before they started building. Pretty scarey.

Ok, I'm ready to lose another client. Won't be the first, won't be the last :wink:

 

[Terrel L. Shields]

In my area, with rare exception, no engineer inspects the soil except in large commercial property.

One or more of three things may be the problem. (speaking as an old soils tech for a civil engineer) First, the soil may not have been properly compacted and formed cavities beneath the slab, often noted by very hollow sound when you tap on it. Lack of reinforcement and poor concrete mix is the second in my mind. Cement plants near coal fired power plants often cut their concrete with fly ash. Very poor stuff and very much will ruin the mix making it soft and friable. Last, soils with high moisture contents often are subject to swelling or heaving and this will destroy pavement or concrete about as quick as anything. Covering the ground with a plastic liner means the clay beneath may be unusually dry (shrinkage) while the edges of the building has clay that expands and contracts with the amount of moisture... If the soil tastes gritty (it won't hurt you) between your teeth it contains some silt or sand. If you cannot see grains and wet it rubs very smoothly between your fingers it may have a high clay content. Red clays tend to swell more than white ones.

 

[Tater Salad]

It's the red stuff. I have the shoes to prove it. Didn't think to eat the stuff--can't imagine what the Realtor would say about me to the loan officer if I had :lol: but I may try that next time if I'm not sure.

I'm still amazed that they don't test the stuff before building! We had a subdivision up north of here that had problems with old underground springs. Here I thought some engineer was gonna have his :!: handed to him on a platter for that one. Maybe there was no engineer to begin with.

Thanks for the insight. Don't think I'll be buying any new tract housing in those parts.

 

[Restrain]

We have very expansive soils in this area. It is not unusual to have to have a foundation company come back a pier a new home due to soil changes. Expansive soils, especially in the dry weather you have been experiencing, can cause enough shifting to shatter any foundation. Definitely recommend a foundation inspection and predicate your report on a negative foundation inspection, i.e., it is assumed that there is no significant settlement that would adversely affect the home. Don't make it 'subject to'. Then, it's up to the borrower and the lender. You've done your job.

 

[Verne Hebert]

I think you should hit the library and study concrete for a while. There is enough concrete in the world that every appraiser should have a basic knowledge.

I concur with the posts. One thing everyone should know is all concrete cracks--the contractor controls the cracking or doesn't. Not always is the cracking internal and appears on the surface. You weren't there so you don't know if the the site was compacted and to what point, if rebar or mesh was used, what the concrete mixture was, or how it was finished.

On clay, a special style of floating slab is the proper installation--I see few of them.

I used to do alot of HUD form inspections prior to pour. I don't do them any more because I don't know is the soil is properly compacted, and I am not there for the finish. At HUD fees, I am not showing up in court 3, 4 , 5 years from now to discuss some homeowners unhappiness with there foundation on my nickel.

 

[Ross (CO)]

Calotz, ..... When you say "spec" home less than 1 year old, do you mean that the builder still owns it and no first-sale to an occupant has taken place ? ....And, there is a Realtor involved, and there is this obvious cracked floor problem in the basement of a home in an environment known for its expansive clays, and you're worried about what your client is going to say, or do, because you will have done the right thing to request a full engineer's inspection ? What kind of client would expect you to turn a blind eye on something so critical as this major aspect affecting the integrity of the construction and the future appeal of this home ? Major floor cracks do not "fix" themselves ! Was this a first home by this builder in this development ? Could they not have fortified the floor with extra concrete thickness like other builders in the area would do ? Was the home under contract to sell and do you think the buyer would be equally concerned ? You are working to protect the buyer, not the Realtor and the builder. Include extra pictures, address the need for the other inspection, conclude your report and don't answer the phone call(s) if the caller i.d. box shows a certain recognized number. Let them leave a message (Bet they won't leave any message -- other than saying "Call me". ) This sounds like a builder warranty issue which all the other parties will have to sort out, not you.

 

[Tater Salad]

Thanks for all the replies

I will do some studying on concrete. What I have studied to this point covered mostly cracks in foundation walls and what they usually mean. This is the first I have seen of a floor crack with no problems on the wall.

Ross--you are right. What kind of a client would get mad? This is a first assignment for a lender that said I came "highly recommended" and gave me a name of someone I didn't know. I must be really good! Anyway, I'm not afraid, just want to sound more knowledgeable if the call comes. So far, no call, so they may be straight. It's much more fun when they do call if they can tell that I'm not just guessing at the problem. I don't want to sound like an idiot defending my position.

Anyway, the builder does still own it. The Realtor works the display home office. I believe that it may be the first one built, but I don't know for sure. I do know that this builder is new to the area, usually builds south of here. They may have no experience with this type of soil.

Pictures are in the file: 3 different angles of the crack, and one of the sad patch job on what I believe is another crack. The pages of my report are numbered so someone will know if they get circular filed.

Ok, caller id, do your thing!

 

[Ted Martin]

I've had the same experience with a new construction. I reported it and everyone (Seller, both agents, lender, buyer) was mad at me. Two weeks later the buyer thanked me for doing my job. Agents, lender and seller are still mad, and haven't figured out that I saved their collective backsides from a lawsuit at a later date when the buyer would have noticed the cracks.